The cost of a missed call, for Chattanooga contractors. The math, the trade averages, and what changes when the numbers are your own.

Step through the calculator with a working-average Chattanooga shop — 80 calls per week, roughly 25% of those missing a live person on the first ring, and a $480 average service ticket — and the math lands on $22,862.40 of monthly recoverable revenue. That is the upper bound on what a fully clean recovery layer could put back on the dispatch board; a real shop typically nets somewhere under that figure, and an under-tuned one nets much less.

The same formula lives on /calculator and on each trade-specific routed calculator (/plumbing/calculator, /hvac/calculator, /electrical/calculator) — and on /pricing as the per-shop worked example. We use it because it is the cleanest way to compare a shop's weekly mix to what the week actually booked, without dragging the answer through a per-call-services model or a marketing-bonus carveout.

If our own math is right, a service-trade operator running the kind of weekly call volume a mid-size Chattanooga shop runs is leaving the equivalent of a senior tech's labor cost on the floor every month — and most of it shows up not in lost jobs but in jobs the next shop took the call on.

• 80 weekly calls is a working average, not a guaranteeSome shops run 40, some run 200. The /calculator lets you punch in your own volume; the trade-specific calculators default to the per-trade norms. Either way the formula is identical.
• 25% miss rate is a working average across the tradesThe miss rate moves around — a one-dispatcher shop on a busy Tuesday can run closer to 35–40% for that hour; a fully-staffed two-line office on a quiet Wednesday can run below 10%. Use 25% as the anchor, then stress-test the calculator against your own call log.
• A 55% close rate is built into the math as a constantThe close rate on a recovered call is held at 55% (CLOSE_RATE_DEFAULT) and is not exposed as a knob. That mirrors what the per-shop audit sees across the trades; it is conservative for warm leads and generous for cold ones, so it does not skew the answer either way.
• $480 average ticket sits in the plumbing $350–500 bandPlumbing shops cluster their jobs inside the $350–500 band, so the /plumbing/calculator and the generic /calculator both default to $480 — the same number the /plumbing proof row publishes. HVAC ($720) and electrical ($880) run higher because their install mix and emergency-diagnostic share pushes the average ticket above the cross-trade $620.

The math is a formula. The number it produces is only as honest as the per-trade averages it leans on. For plumbing, HVAC, and electrical — the three trades the trade pages cover — we publish a small set of proof bullets on /plumbing, /hvac, and /electrical, and those numbers are what carries the formula into a defensible monthly figure for your vertical. The calculator gives the formula, the trade pages give the per-vertical numbers, the audit gives the per-shop numbers.

These are not invented stats. They are the cross-trade averages the install is tuned against, drawn from the trade-page proof points and re-used on the per-trade routed calculators so the starting average ticket is the same number the trade page is published with. The post leans on exactly that chain — and where it diverges from your shop, the audit fills it back in from your last quarter's invoices.

• $480 average ticket · PlumbingThe /plumbing proof point — pin-hole repairs, water-heater swaps, and the after-hours premium jobs that drive the recovery numbers. The /plumbing/calculator defaults to $480 so the formula lands here the same way the trade page describes it.
• 30% after-hours share · PlumbingRoughly three in ten inbound plumbing calls land outside office hours. That is the recovery layer we get paid for — the calls the dispatcher would have missed asleep. Same shape as the no-cool Tuesday war story on /hvac.
• $720 average ticket · HVACThe /hvac proof point — install mix, refrigerant line repairs, and emergency diagnostics pulling the average ticket above $620. The /hvac/calculator starts at $720 for the same reason.
• 38 missed calls/hr on peak no-cool days · HVACTuesday 90°F+ windows stack the inbound into a single peak hour. The recovery layer turns the missed-call slot into a confirmed booking without the dispatcher juggling three lines — same war story the playbook on /resources/missed-call-recovery-playbook walks.
• $880 average ticket · ElectricalThe /electrical proof point — panel upgrades, service upgrades, and EV-charger install mix push the average job above the cross-trade $620, and the after-hours emergency diagnostic lift pushes the average above HVAC’s $720. The /electrical/calculator starts at $880.
• Storm-mean recovery within 4 hours · ElectricalWhen the storm wakes the line at 3am, the recovery layer turns the inbound into a confirmed slot before the dispatcher has finished the coffee — same-day diagnostics are the rule, not the exception.

The same numbers above appear, in different shapes, across the rest of the funnel. The playbook on /resources/missed-call-recovery-playbook walks the 3-touch SMS cadence that turns that recovered-call slot into a confirmed booking on whichever dispatch board the shop already runs — and a booking that doesn't land is a call Holdfast doesn't get paid on. The per-shop worked example on /pricing shows how the bonus bills against the booking, not against the recovery, so the math lines up for both sides of the invoice.

If your shop is the kind that has its own call log and ticket history ready to walk, the audit-request intake is the fastest next step — a 20-minute audit pulls ten of your recent inbound calls and your last quarter's ticket values to fill the same inputs from real numbers. No install, no commitment, the same per-shop sheet the pricing page walks through.

• Read the missed-call recovery playbookThe /resources/missed-call-recovery-playbook walks the first 30 seconds on a recovered call, the 3-touch SMS cadence, and the booking handoff. The post is the math; the playbook is the operations.
• Read the per-shop worked example on /pricingThe /pricing worked example shows how the retainer + per-booked-job bonus line items tie back to the same monthly recovery number the calculator produces — the trade-off is between an upper bound and the invoice that gets billed against it.
• Read /calculator or punch in your own numbersThe /calculator route is the editable form of the math in this post — same formula, same close-rate constant, but the weeklyCalls / missedRate / avgTicket inputs are yours. The per-trade routed variants default to the trade-page numbers above.
• Book a 20-minute auditThe /audit-request intake is the place to ask for the per-shop reshape — ten real calls, last-quarter ticket values, and a per-shop sheet within a few days. No install, no commitment.